Alert archive / North Carolina / Mesoscale Discussions in 2019

Mesoscale Discussion 913

May 31, 201928 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at May 31, 2019, 4:43 PM EDT for 28 counties in North Carolina. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
May 31, 2019, 4:43 PM EDT (20:43 UTC)
Expired
May 31, 2019, 5:45 PM EDT
In force
62 min
Issued by
the Storm Prediction Center
All 28 counties

Alamance County, NC, Anson County, NC, Cabarrus County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Durham County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Rowan County, NC, Stanly County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC

The radar

The Raleigh/Durham radar (KRAX), 78 km from the middle of the area, began a volume at 20:44 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.7 hours before the alert went out and 58 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2019-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 62 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2019-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
62 J/kg
Mixed-layer CIN
-125 J/kg
Mixed-layer LCL
1499 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

762 
ACUS11 KWNS 312044
SWOMCD
SPC MCD 312043 
NCZ000-VAZ000-SCZ000-312145-

Mesoscale Discussion 0913
NWS Storm Prediction Center Norman OK
0343 PM CDT Fri May 31 2019

Areas affected...NC Piedmont

Concerning...Severe Thunderstorm Watch 300...

Valid 312043Z - 312145Z

The severe weather threat for Severe Thunderstorm Watch 300
continues.

SUMMARY...Large hail and scattered wind damage (due to isolated
severe gusts) are probable over the next several hours as storms
over western NC move into central NC.

DISCUSSION...Radar mosaic shows a myriad of small-scale thunderstorm
outflow boundaries and the effective sea breeze boundary slowly
pushing into east-central and central parts of NC.  The area near
the Research Triangle has been largely void of thunderstorms through
mid afternoon.  However, as an eastward migrating, mid-level
shortwave trough moves into western VA/western NC early this
evening, expecting storm development to increase across central NC
late this afternoon.  KRAX VAD data shows 40kt flow at 6km AGL
increasing to 60kt at 9km.  Surface dewpoints have mixed into the
lower 60s across the NC Piedmont resulting in 25-30 degree
temperature spreads.  The ample flow in the mid levels coupled with
storms moving into a more moisture-rich airmass (near I-95) will
favor robust storm development---including weak supercells and
episodic severe multicells.  Large hail will favor the supercell
storms and the well-mixed boundary layer will promote efficient
downdrafts capable of wind damage and isolated severe gusts (around
60mph) with the more intense storms.

..Smith.. 05/31/2019

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...AKQ...RAH...ILM...RNK...GSP...

LAT...LON   36547808 36557907 36108035 35708071 35498092 34978054
            34797978 35507823 36297748 36547808

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 30, 8:02 PM EDTMesoscale DiscussionSPCBeaufort, Bladen, Carteret, Chowan, Columbus, Craven and 18 more58 min
May 31, 12:07 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Burke, Cabarrus and 41 more113 min
May 31, 1:29 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Anson, Ashe, Beaufort and 76 more10 hr
May 31, 7:22 PM EDTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Cabarrus and 59 more83 min

Nearby

Mesoscale Discussions in North Carolina, 2019Every mesoscale discussion in 2019

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.